Hope for polluted cities: Daan Roosegaarde, a Dutch artist and innovator has created the Smog Free Tower

China will deploy world's largest outdoor air purifier designed by a Dutch engineer in its smog- hit capital Beijing, as the thick heavily-polluted haze returned to haunt the city, driving people indoors. The seven-meter-tall tower can capture about 75% of PM 2.5 and PM 10 tiny particles in its vicinity and then release purified air to create a “bubble” of fresh air around it.The tower can clean 30,000 cubic metres of air per hour through its patented ozone-free ion technology.